A night vision goggle is a special use device which amplifies very low levels of light to make night viewing possible. A user can thus see and move in extremely low-light situations. Although night vision goggles have a variety of uses, they are particularly important in the field of military night operations. In their most prominent use, night vision goggles allow troops to maneuver in almost complete darkness.
Night vision goggles operate on a principle in which the light reflections of dimly lit objects are amplified many times by an image intensifying tube, and then projected on an integral phosphor-coated display screen. A viewer using such equipment can look through eyepieces and see an amplified representation of an object on the screen.
The use of night vision goggles can, however, create a security problem for the user, because of the green glow of the image emitted from the phosphor-coated screen. Even very small amounts of this glow which might escape around the eyepieces may form a target for unfriendly forces, particularly if they are also equipped with night vision devices.
Previous eyecup designs employ a pair of flexible hollow eyecups, each with a flat end which interfaces the goggle to the user's individual eyes. Since these prior used eyecups do not adequately conform to the contours of the user's facial features, light from the phosphor-coated display screen can escape from around the eyecups and be detected by others.
From the foregoing, it may be seen that a need has arisen for an eyecup which provides an effective ocular seal conforming very closely to the facial features of users in general.